Posts about Life Science

The Challenge of Protecting Us from Evolving Bacterial Threats

I have long been concerned about the practices we continue to use increasing the risks of “superbugs.” I have written about this many times, including: The Overuse of Antibiotics Carries Large Long Term Risks (2005)Are you ready for a world without antibiotics? (2010), Antibiotics Breed Superbugs Faster Than Expected (2010), Entirely New Antibiotic (platensimycin) Developed (2006), Our Poor Antibiotic Practices Have Sped the Evolution of Resistance to Our Last-Resort Antibiotic (2015).

I do also believe the wonderful breakthroughs we make when we invest in science and engineering have made our lives much better and have the potential to continue to do so in many ways, including in dealing with the risks of superbugs. But this is something that requires great effort by many smart people and a great deal of money. It will only happen if we put in the effort.

Winning war against ‘superbugs’

hey won this particular battle, or at least gained some critical intelligence, not by designing a new antibiotic, but by interfering with the metabolism of the bacterial “bugs” — E. coli in this case — and rendering them weaker in the face of existing antibiotics

ROS, or “reactive oxygen species,” include molecules like superoxide and hydrogen peroxide that are natural byproducts of normal metabolic activity. Bacteria usually cope just fine with them, but too many can cause serious damage or even kill the cell. In fact, Collins’ team revealed a few years ago the true antibiotic modus operandi: they kill bacteria in part by ramping up ROS production.

We need to continue to pursue many paths to protecting us from rapidly evolving bacterial risks. Many promising research results will fail to produce usable solutions. We need to try many promising ideas to find useful tools and strategies to protect human health.

Using Rats to Sniff Out TB

Apopo’s African giant pouched rats are being used to sniff out mines and TB

In the face of what the World Health Organisation is calling a global TB epidemic, an innovative tech startup named Apopo is attempting to reverse the harrowing statistics, using rodents to sniff out TB in cough and spit samples.

No ordinary lab rats, Apopo’s African giant pouched rats – affectionately named HeroRats – are extremely sensitive to smell, with more genetic material allocated to olfaction than any other mammal species. They are also highly social animals, and can be trained to communicate with humans.

I have written about these wonderful rats previously, Appropriate Technology: Rats Helping Humans by Sniffing Out Land Mines. As I have stated many time I especially enjoy engineering solutions that use affordable and effective methods to help everyone.

Photo of Hero-rat detecting TB in Mozambique with Apopo staff person

Hero-rat detecting TB in Mozambique

A DNA-screening device that takes up to two hours to analyse each individual sample with 95pc accuracy costs $17,000 and thousands more in upkeep. By contrast, a HeroRat costs $6,500 to train, can probe through hundreds of samples every hour [70-85% accuracy rate], and requires only food, water and cages for shelter.

Keep these innovations coming. The USA needs them also given the massively costly healthcare system in the USA.

The TB sniffing rat program was developed through Apopo in Tanzania.

Related: Rats Show Empathy-driven BehaviorBeehive Fence Protects Farms from ElephantsTuberculosis Risk (2007)Dangerous Drug-Resistant Strains of TB are a Growing Threat (2012)

An Eukaryote that Completely Lacks Mitochondria

If you don’t have any idea what the title means that is ok. I probably wouldn’t have until the last 15 years when I found how interesting biology is thanks to the internet and wonderful resources online making biology interesting. I hope you find learning about biology as interesting as I do.

Look, Ma! No Mitochondria

Mitochondria have their own DNA, and scientists believe they were once free-living bacteria that got engulfed by primitive, ancient cells that were evolving to become the complex life forms we know and love today.

What they learned is that instead of relying on mitochondria to assemble iron-sulfur clusters, these cells use a different kind of machinery. And it looks like they acquired it from bacteria.

The researchers say this is the first example of any eukaryote that completely lacks mitochondria.

However, the results do not negate the idea that the acquisition of a mitochondrion was an important and perhaps defining event in the evolution of eukaryotic cells, he adds.

That’s because it seems clear that this organism’s ancestors had mitochondria that were then lost after the cells acquired their non-mitochondrial system for making iron-sulfur clusters.

Biology is amazing and mitochondria are one of the many amazing details. I wish so much that my education could have given biology a tiny fraction of the interest I have found it in after school.

Related: Human Gene Origins: 37% Bacterial, 35% Animal, 28% EukaryoticOne Species’ Genome Discovered Inside Another’sParasite Evolved from Cnidarians (Jellyfish etc.)Plants, Unikonts, Excavates and SARs

Webcasts on the Human Microbiome

The human microbiome is a very interesting aspect of our health and biology.

The 99% figure they quote is mainly silly. It might be technically accurate, but it is much more misleading than accurate (if it is accurate). We have more non-human cells than human but those cells are much smaller and we are overwhelmingly made up of human cells by weight (95+%).

The complexity of healthy bodies is far from understood. It is interesting to watch our understanding of the balancing act going on inside of us. Many foreign “invaders” are critical to our health.

Related: People are Superorganisms With Microbiomes of Thousands of SpeciesPeople Have More Bacterial Cells than Human CellsFighting Superbugs with Superhero BugsWe Have Thousands of Viruses In Us All the Time

Continue reading

Using Diatom Algae to Deliver Chemotherapy Drugs Directly to Cancer Cells

I am thankful for scientists doing the time consuming and important research to find new ways to fight disease. Here is an interesting webcast discussing how chemotherapy is used to fight cancer and how scientists are looking to algae to deliver the chemotherapy drugs to better target cancer cells (while not savaging our health cells).

I am also thankful to the funding sources that pay for this research (and for cool explanations of science, like SciShow).

Read more about the genetically engineered algae kills 90% of cancer cells without harming healthy ones. The algae are a diatom and many diatoms look very cool.

Sadly the actual research paper (by government funded university professors) is published by a closed science publisher (when are we finally going to stop this practice that was outdated over a decade ago?). Thankfully those responsible for SciShow are much more interested in promoting science than maintaining outdated business models (in direct contrast to so many science journal publishers).

Related post on cool delivery methods for life saving drugs: Using Bacteria to Carry Nanoparticles Into CellsSelf-Assembling Cubes Could Deliver Medicine (2006)Nanoparticles With Scorpion Venom Slow Cancer SpreadNASA Biocapsules Deliver Medical Interventions Based Upon What They Detect in the Body

Parasite Evolved from Cnidarians (Jellyfish etc.)

This is another instance of science research providing us interesting details about the very odd ways life has evolved on earth.

Genome sequencing confirms that myxozoans, a diverse group of microscopic parasites that infect invertebrate and vertebrate hosts, are actually highly reduced cnidarians — the phylum that includes jellyfish, corals and sea anemones.

“This is a remarkable case of extreme degeneration of an animal body plan,” said Paulyn Cartwright, associate professor of ecology and evolutionary biology at the University of Kansas (KU) and principal investigator on the research project. “First, we confirmed they’re cnidarians. Now we need to investigate how they got to be that way.”

images of myxozoans parasite spores and a jellyfish

Not only has the parasitic micro jellyfish evolved a stripped-down body plan of just a few cells, but via data generated at the KU Medical Center’s Genome Sequencing Facility researchers also found the myxozoan genome was drastically simplified.

“These were 20 to 40 times smaller than average jellyfish genomes,” Cartwright said. “It’s one of the smallest animal genomes ever reported. It only has about 20 million base pairs, whereas the average Cnidarian has over 300 million. These are tiny little genomes by comparison.”

Despite its radical phasedown of the modern jellyfish’s body structure and genome over millions of years, Myxozoa has retained the essential characteristic of the jellyfish — its stinger, or “nematocyst” — along with the genes needed to make it.

“Because they’re so weird, it’s difficult to imagine they were jellyfish,” she said. “They don’t have a mouth or a gut. They have just a few cells. But then they have this complex structure that looks just like stinging cell of cnidarian. Jellyfish tentacles are loaded with them — little firing weapons.”

The findings are the stuff of scientific fascination but also could have a commercial effect. Myxozoa commonly plague commercial fish stock such as trout and salmon.

“They’re a very diverse group of parasites, and some have been well-studied because they infect fish and can wreak havoc in aquaculture of economic importance,” Cartwright said.

Continue reading

Fighting Superbugs with Superhero Bugs

As concerns over deadly antibiotic-resistant strains of ‘superbug’ bacteria grow, scientists at the Salk Institute are offering a possible solution to the problem: ‘superhero’ bacteria that live in the gut and move to other parts of the body to alleviate life-threatening side effects caused by infections.

Salk researchers reported finding a strain of microbiome Escherichia coli bacteria in mice capable of improving the animals’ tolerance to infections of the lungs and intestines by preventing wasting–a common and potentially deadly loss of muscle tissue that occurs in serious infections. If a similarly protective strain is found in humans, it could offer a new avenue for countering muscle wasting, which afflicts patients suffering from sepsis and hospital-acquired infections, many of which are now antibiotic resistant.

images of E. coli bacteria, salmonella typhimurium and burkholderia thailandensis

Salk scientists found a strain of E. coli bacteria (left) that were able to stop muscle wasting in mice infected with either Salmonella Typhimurium (center) and Burkholderia thailandensis (right). Image courtesy the Salk Institute.

“Treatments for infection have long focused on eradicating the offending microbe, but what actually kills people aren’t the bacteria themselves–it’s the collateral damage it does to the body,” says Janelle Ayres, a Salk assistant professor in the Nomis Foundation Laboratories for Immunobiology and Microbial Pathogenesis and senior researcher on the study.

“Our findings suggest that preventing the damage–in this case muscle wasting–can stave off the most life-threatening aspects of an infection,” she adds. “And by not trying the kill the pathogen, you’re not encouraging the evolution of the deadly antibiotic-resistant strains that are killing people around the world. We might be able to fight superbugs with ‘superhero’ bugs.”

Once the most powerful and revolutionary of drugs, antibiotics appear to have reached their limits, due to the ability of bacteria to rapidly evolve resistance to the medicines. The rise of antibiotic resistance presents a grave threat to people around the world, as diseases once easily controlled repel all attempts at treatment. A recent study found that up to half of the bacteria that cause infections in US hospitals after a surgery are resistant to standard antibiotics.

In the United States alone, two million people annually become infected with bacteria that are resistant to antibiotics and at least 23,000 people die each year as a direct result of these infections, according to the U.S. Centers for Disease Control.

Continue reading

Youyou Tu: The First Chinese Woman to Win a Nobel Prize

The Nobel Prize in Physiology or Medicine 2015 was divided, one half jointly to William C. Campbell (born Ireland, now USA) and Satoshi Ōmura (Japan) “for their discoveries concerning a novel therapy against infections caused by roundworm parasites” and the other half to Youyou Tu (China) “for her discoveries concerning a novel therapy against Malaria”.

Youyou Tu is the first Chinese woman to win a Nobel Prize.

Diseases caused by parasites have plagued humankind for millennia and constitute a major global health problem. In particular, parasitic diseases affect the world’s poorest populations and represent a huge barrier to improving human health and wellbeing. This year’s Nobel Laureates have developed therapies that have revolutionized the treatment of some of the most devastating parasitic diseases.

William C. Campbell and Satoshi Ōmura discovered a new drug, Avermectin, the derivatives of which have radically lowered the incidence of River Blindness and Lymphatic Filariasis, as well as showing efficacy against an expanding number of other parasitic diseases. Youyou Tu discovered Artemisinin, a drug that has significantly reduced the mortality rates for patients suffering from Malaria.

These two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually. The consequences in terms of improved human health and reduced suffering are immeasurable.

image of Artemisinin

via Noble Prize website

Malaria was traditionally treated by chloroquine or quinine, but with declining success. By the late 1960s, efforts to eradicate Malaria had failed and the disease was on the rise. At that time, Youyou Tu in China turned to traditional herbal medicine to tackle the challenge of developing novel Malaria therapies. From a large-scale screen of herbal remedies in Malaria-infected animals, an extract from the plant Artemisia annua emerged as an interesting candidate.

However, the results were inconsistent, so Tu revisited the ancient literature and discovered clues that guided her in her quest to successfully extract the active component from Artemisia annua. Tu was the first to show that this component, later called Artemisinin, was highly effective against the Malaria parasite, both in infected animals and in humans. Artemisinin represents a new class of antimalarial agents that rapidly kill the Malaria parasites at an early stage of their development, which explains its unprecedented potency in the treatment of severe Malaria.

Youyou Tu was born in 1930 in China and is a Chinese citizen. She graduated from the Pharmacy Department at Beijing Medical University in 1955. From 1965-1978 she was Assistant Professor at the China Academy of Traditional Chinese Medicine, from 1979-1984 Associate Professor and from 1985 Professor at the same Institute. From 2000, Tu has been Chief Professor at the China Academy of Traditional Chinese Medicine. She doesn’t have a doctorate, very rare for a Nobel Prize winner in the sciences.

Read the full press release

Related: Nobel Prize in Physiology or Medicine 2012 for Reprogramming Cells to be PluripotentNobel Prize in Physiology or Medicine 2008Parasites in the Gut Help Develop a Healthy Immune System2011 Nobel Prize in Physiology or MedicineVideo showing malaria breaking into cell

Cancer Rates Consistent Across Species Instead of Increasing Due to Body Mass

It would seem sensible to think cancer should be more prevalent in species with a huge number of cells, and thus more cells to become cancerous. But cancer risk doesn’t increase in this way. This interesting, open source paper, sheds some light on what is behind this.

Solutions to Peto’s paradox revealed by mathematical modelling and cross-species cancer gene analysis

Whales have 1000-fold more cells than humans and mice have 1000-fold fewer; however, cancer risk across species does not increase with the number of somatic cells and the lifespan of the organism. This observation is known as Peto’s paradox. How much would evolution have to change the parameters of somatic evolution in order to equalize the cancer risk between species that differ by orders of magnitude in size? Analysis of previously published models of colorectal cancer suggests that a two- to three-fold decrease in the mutation rate or stem cell division rate is enough to reduce a whale’s cancer risk to that of a human. Similarly, the addition of one to two required tumour-suppressor gene mutations would also be sufficient.

We surveyed mammalian genomes and did not find a positive correlation of tumour-suppressor genes with increasing body mass and longevity. However, we found evidence of the amplification of TP53 in elephants, MAL in horses and FBXO31 in microbats, which might explain Peto’s paradox in those species. Exploring parameters that evolution may have fine-tuned in large, long-lived organisms will help guide future experiments to reveal the underlying biology responsible for Peto’s paradox and guide cancer prevention in humans.

Elephants in Kenya

Elephants in Kenya by John Hunter. See more photos from my trip to Kenya.

In another way it would make sense that large animals would have hugely increased risks of cancer. As they evolved, extremely high cancer rates would be a much bigger problem for them. Therefore it wouldn’t be surprising to find they have evolved a way of reducing cancer risks.

Despite these limitations, we found genes that have been dramatically amplified in specific mammalian genomes, the most interesting of which is the discovery of 12 TP53 copies in the genome of the African elephant. We subsequently cloned those genes and identified 19 distinct copies of TP53 in African elephants and 15–20 in Asian elephants [1]. Another potential lead for solving Peto’s paradox is MAL, which is found to have eight copies in the horse genome and two in microbat. This could be an example of convergent evolution where a large animal (horse) and a small, long-lived animal (microbat) both evolved extra copies of the same gene to overcome their increased risk of cancer. Further analysis and experimentation would need to be performed to determine the function of these copies and whether or not they provide enhanced suppression of carcinogenesis.

The researchers have found an interesting potential explanation for how that has been accomplished.

Related: The Only Known Cancerless Animal (the naked mole rat)Webcast of a T-cell Killing a Cancerous CellResearchers Find Switch That Allows Cancer Cells to SpreadCancer Vaccines

In Many Crops Ants Can Provide Pest Protection Superior or Equal to Chemicals at a Much Lower Cost

Ants are as Effective as pesticides

The review [of over 70 studies] was conducted by Aarhus University’s Dr Joachim Offenberg, an ecologist who has studied ants for almost 20 years. It includes studies of more than 50 pest species on nine crops across eight countries in Africa, South-East Asia and Australia.

Most of the studies in Offenberg’s review are on weaver ants (Oecophylla), a tropical species which lives in trees and weaves ball-shaped nests from leaves. Because weaver ants live in their host trees’ canopy, near the flowers and fruit that need protection from pests, they are good pest controllers in tropical orchards.

All farmers need to do is collect ant nests from the wild, hang them in plastic bags among their tree crops and feed them a sugar solution while they build their new nests. Once a colony is established, farmers then connect the trees that are part of the colony with aerial ‘ant walkways’ made from string or lianas.

After that, the ants need little, except for some water in the dry season (which can be provided by hanging old plastic bottles among the trees), pruning trees that belong to different colonies so that the ants do not fight, and avoiding insecticide sprays.

The review shows that crops such as cashew and mango can be exceptionally well protected from pests by weaver ants.

One three-year study in Australia recorded cashew yields 49% higher in plots patrolled by ants compared with those protected by chemicals. Nut quality was higher too, so net income was 71% higher with ants than with chemicals.

Similar studies in Australian mango crops found that ants could produce the same yield as chemical control, but because the ants were cheaper, and fruit quality better, net income from mangoes produced with ant protection was 73% higher.

Those crops are special cases in which the ants are vastly superior. But in many other cases ants are as effective and much cheaper than chemical options. Different species of ants are suited to protecting different types of drops. Weaver ants require a canopy, other ants can protect crops without a canopy.

I hope more farmers adopt ants to help protect their crop yields.

Related: Pigs Instead of PesticidesWhy Don’t All Ant Species Replace Queens in the Colony, Since Some DoHow To Make Your Own Pesticide with Ingredients from Your KitchenAnother Bee Study Finds CCD is Likely Due to Combination of Factors Including Pesticides (2013)

Exercise Is Really Really Good for You

Nice webcast that reviews the benefits of exercise that are confirmed by medical studies.

Other than [not] smoking there are few modifiable risk factors that seem to have the huge impact on heath activity does…

150 minutes a week of moderate (walking briskly, biking, even mowing the lawn maybe) activity (30 minutes a day 5 days a week) is a decent target for a minimum amount of activity for most people. I have not bought a car since my move (2 months ago) and walk to the grocery store, library, bank, subway, restaurants which is easily 30 minutes and usually more each trip. And for further away places I am biking.

Another option is 25 minutes of vigorous activity 3 times a week and 2 days a week of weight training. Basketball is my favorite form of vigorous activity and sometimes my biking and yard work reach that mark. I like swimming (and I did swim a fair amount when I had a pool at my condo but I don’t swim now as it isn’t right downstairs from my bedroom). I like vigorous activity as I end up feeling refreshed and it serves as a noticeable form of stress release for me.

Related: Better Health Through Exercise, Not Smoking, Low Weight, Healthy Diet and Low Alcohol IntakeExamining the Scientific Basis Around Exercise and Diet ClaimsInactivity Leads to 5.3 Million Early Deaths a Year

  • Recent Comments:

    • samaira khatri: Exercise can help prevent excess weight gain or help maintain weight loss. When you engage...
    • Sherry: Love the idea of science toys! STEM toys are just amazing these days but isn’t it better to...
    • Marbella: This was really interesting. Thanks for sharing.
    • MIT: I’ve heard of animals being used to sniff out cancer before, but I’ve never heard of them...
    • Piazza Dei Fiori: Well….making my girlfriend very happy, that is what flowers are for…
    • Simon: non-smoking people exceed and excel in life expectancy and in fitness and quality of life, There is...
    • Conrad: I’m glad I was able to come back and watch the video. It is ever so interesting that someone...
    • Conrad: The success numbers in the original article speaks volumes about what these rats can do in low...
  • Recent Trackbacks:

  • Links